[goffice] GOImage: create an unknown image placeholder when no image data is given.

[Morten Welinder <mortenw src gnome org>]

commit 8a01ed6d6ee089d5d633708228dde19bd029f65a
Author: Morten Welinder <terra gnome org>
Date:   Fri Feb 27 13:23:23 2015 -0500

    GOImage: create an unknown image placeholder when no image data is given.

 ChangeLog                |    5 +++++
 goffice/utils/go-image.c |    7 +++++--
 2 files changed, 10 insertions(+), 2 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 9ffa4ab..77ba2a7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2015-02-27  Morten Welinder  <terra gnome org>
+
+       * goffice/utils/go-image.c (go_image_new_from_data): If no image
+       data is given, create an unknown image placeholder.
+
 2015-02-24  Morten Welinder  <terra gnome org>
 
        * goffice/graph/gog-series-labels.c (gog_data_label_finalize):
diff --git a/goffice/utils/go-image.c b/goffice/utils/go-image.c
index f970d18..d80a5fd 100644
--- a/goffice/utils/go-image.c
+++ b/goffice/utils/go-image.c
@@ -287,7 +287,7 @@ go_image_get_format_from_name (char const *name)
 {
        unsigned i;
 
-       if (name == NULL)
+       if (name == NULL || strcmp (name, "unknown") == 0)
                return GO_IMAGE_FORMAT_UNKNOWN;
 
        go_image_build_pixbuf_format_infos ();
@@ -653,7 +653,10 @@ go_image_new_from_data (char const *type, guint8 const *data, gsize length, char
                g_warning ("unrecognized image format");
                return NULL;
        }
-       if (!strcmp (type, "svg")) {
+       if (data == NULL || length == 0) {
+               image = NULL;
+               type = "unknown";
+       } else if (!strcmp (type, "svg")) {
                image = go_svg_new_from_data (data, length, error);
        } else if (!strcmp (type, "emf") || !strcmp (type, "wmf")) {
                image = go_emf_new_from_data (data, length, error);